Reversible ribbon feed device

ABSTRACT

A device for reversing the direction of feeding of an inked ribbon which is bidirectionally fed between a pair of reels by selectively causing one or the other of the reels to rotate and takeup the ribbon thereon. A scissorlike member is located between the two reels with its arms biased against the peripheries of the rolls of ribbon on the reels. A pair of pressure-actuated switches, each of which is responsive to the position of one of the scissor arms, is provided to effect selective engagement of the reels with a motor by controlling electrically operated clutches. When a scissor arm becomes positioned to indicate that a predetermined low amount of ribbon is on one of the reels, one of the switches responds by drivingly engaging that reel with the motor while substantially disengaging the other reel from the motor. In this manner, the direction of ribbon feed is reversed. Preferably, the device also comprises a detachable cartridge within which the scissorlike member and reels are mounted.

o United tates atent [72] Inventor John D. Read Ashland, Mass. [21]Appl. No. 858,378 [22] Filed Sept. 16, I969 [45] Patented Jan. 4, I972[73] Assignee Mohawk Data Sciences Corp.

Herkimer, N.Y.

[54] REVERSIBLE RIBBON FEED DEVICE 8 Claims, 6 Drawing Figs.

[52] US. Cl 242/67.4, 197/160, 242/187, 242/201 [51] Int. Cl B65h 17/02[50] Field of Search 242/55,

[56] References Cited UNITED STATES PATENTS 3,051,405 8/1962 Lyon242/187 3,102,699 9/1963 Proctor 242/187 3,235,197 2/1966 Johnson et al.242/67.4 3,266,745 8/ 1966 Benson 242/67.4 3,443,504 5/1969 Rose et al.242/67.4

OTHER REFERENCES IBM Technical Disclosure Bulletin, J. O. Schaefer, Vol.5, No. 12; 5- 1963;

Primary ExaminerStan1ey N. Gilreath Assistant Examiner-Werner H.Schroeder Attorneys-Francis J. Thomas, Richard H. Smith, Thomas C.Siekman and Sughrue, Rothwell, Mion, Zinn and Macpeak ABSTRACT: A devicefor reversing the direction of feeding of an inked ribbon which isbidirectionally fed between a pair of reels by selectively causing oneor the other of the reels to rotate and takeup the ribbon thereon. Ascissorlike member is located between the two reels with its arms biasedagainst the peripheries of the rolls of ribbon on the reels. A pair ofprossureactuated switches, each of which is responsive to the positionof one of the scissor arms, is provided to effect selective engagementof the reels with a motor by controlling electrically operated clutches.When a scissor arm becomes p0sitioned to indicate that a predeterminedlow amount of ribbon is on one of the reels, one of the switchesresponds by drivingly engaging that reel with the motor whilesubstantially disengaging the other reel from the motor. In this manner,the direction of ribbon feed is reversed. Preferably, the device alsocomprises a detachable cartridge within which the scissorlike member andreels are mounted.

PATENTEUM 4E7? SHEET 1 OF 4 cul INVENTOR JOHN D. READ BY,

W JM

ATTORNEY PATENTEBJRH 4B7? 3.632.052

SHEET 3 [1F 4 CLUTCH CLUTCH -28 HOLD 57 CURRENT DRIVER 0 1 DRIVER DRIVER1 I 1 l I O FF 50 S R I57 L v/ Ho II FIG. 30

PATENTED JAN 4 H72 SHEET 0F 4 FIG. 3

FIG.5

BACKGROUND OF THE INVENTION The present invention relates to areversible device for bidirectionally feeding an elongated web between apair of reels and, more particularly, to such a device for feeding theinked ribbon of a high-speed printer or similar machine.

In many of the high-speed printers used in data processing, charactersare imprinted by selectively forcing a ribbon and paper against typecharacters on a rotating drum or chain. The ribbon is fed across thepaper from a first to a second reel so that a new area of the ribbon iscontinually being made available during the printing operation. Sincethe used areas of the ribbon regain ink from other areas by capillaryaction, the ribbons direction of feeding is reversed and the ribbon isagain used while being fed back across the paper. This process ofalternately reversing the direction of feeding the ribbon continuesuntil an insufficient amount of ink remains. The ribbon is then removedand replaced.

SUMMARY OF THE INVENTION According to the invention, a device isprovided to reverse the direction in which an inked ribbon or otherelongated web is fed between a pair of reels by selectively rotating oneof the other of the reels to takeup the ribbon thereon. The devicecomprises a scissorlike member whose arms are biased against theperipheries of the rolls of ribbon on the reels. Electrically controlledmeans is provided to selectively rotate either of the reels in responseto the positions of the scissor arms. The direction of ribbon feedingmay be reversed when a predetermined low amount of ribbon occurs on oneof the reels. Preferably, the reels and scissorlike member are mountedwithin a cartridge which may be easily removed and replaced when the inkon the ribbon has been used.

The ribbon-reversing device of the invention is simple in design,reliable in use and inexpensive to manufacture. With the reels andscissorlike member mounted within a cartridge, an easily replaceable,transportable and storable device is provided.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 shows a preferred embodiment ofa reversible ribbon feed device according to the invention.

FIG. 2 is a section taken along line 2-2 of FIG. 1.

FIGS. 3 and 3a are sections taken along lines 33 and 3a- 30 l in FIG. 1respectively and illustrate the manner in which the cartridge ismounted.

FIG. 4 is a schematic diagram of a suitable control circuit for theribbon feed device.

FIG. 5 is an elevation view of the cartridge as stored with one of thereels removed.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, a device forbidirectionally feeding an inked ribbon l is shown mounted on a panel 2which may, for example, be part of the housing for a high-speed printer.The device contains a pair of reels, 3 and 4, between which the ribbonis fed. Both reels payout ribbon when rotating clockwise and takeupribbon when rotated counterclockwise. Initially, the ribbon may be fedfrom the righthand reel 3 to the left-hand reel 4 and, when apredetermined amount of ribbon has been thus fed and the ribbon on theright-hand reel 3 is almost depleted, the direction of feeding isreversed. A scissorlike member 5 having a pair of scissor arms, 6 and 7,is located between the reels with the scissor arms maintained in contactwith the peripheries of the rolls of ribbon on the reels. Flanges, 8 and9, are located on the scissor arms at the points of contact.

Referring to both FIGS. 1 and 2, the reels and scissorlike member arecontained within a cartridge which is detachably mounted on the panel 2of the printer housing. The cartridge comprises an open-bottomed,preferably plastic, rectangular housing 10 whose bottom edges adjoin thepanel. Holes 10a are provided in the short sides of the housing to allowthe ribbon to pass from one reel, out of the cartridge, past theprinter's typing mechanism (not shown) and across the paper (not shown),back into the cartridge, and onto the other reel. Preferably, the ribbonhas a short noninked end section which may be placed over the properpath from one reel to the other by the printer's operator withoutsoiling his hands with ink when mounting the cartridge on the printer.

Flanges ll, shown in FIGS. 3 and 3a, are attached to the bottom edges ofthe housing's long sides, 12 and 12a. These flanges cooperate with lips13 on a pair of mounting members, 14 and 15, which are permanentlysecured to the panel. One of the mounting members 14 extends along theentire length of one of the housing's long sides I2, while the othermounting member 15 is shorter and abuts the housings opposite side 12a.When mounting the cartridge on the panel, the flange 11 on side 12 isinitially placed under the lip 13 of the linger mounting member 14 asindicated in FIG. 3. The flange 11 on side 12a is then placed under thelip 13 of the shorter mounting member 15 by merely pushing down on thehousing 10 adjacent side 12a. As shown in FIG. 3a, a beveled end on thisflange slides over the lip 13 to allow such ease of placement. To removethe cartridge, the side 12a adjacent the shorter mounting member 15 isdeflected sufficiently for its flange 12 to clear the lip 13 of theshorter mounting member 15. A pair of pegs 16 is located on the panel tomaintain, and aid in, correct placement of the cartridge.

As best shown in FIGS. 2 and 5, the scissorlike member 5 has a pair ofsleeves, l7 and 18, each of which is integral with one of the scissorarms concentric about the scissorlike members pivot point. The sleevessurround a member 19 projecting from the top 20 of the housing 10. Thescissorlike member is retained on the member 19 by a retaining ring 21and thereby mounted from the top 20 of the housing. The projectingmember 19 is also surrounded by a torsional spring 22 located betweenthe two scissor arms, 6 and 7. The two ends of the spring 22 are bent toproject through holes 23 (FIG. I) in the scissor arms so that the springbiases the arms away from each other and in contact with the peripheriesof the rolls of ribbon on the reels.

As illustrated in FIG. 2, the reels are mounted from the top 20 of thehousing by projections 24 which extend through openings at their centersand about which the reels are rotatable. The reels are held in placebetween retaining rings 25 secured at the bottom of the projections 24,and bosses 26 surrounding the projections adjacent the top 20 of thehousing.

These projections extend past the reels and locate in bores 27 withinelectromagnetic clutches 28 of well-known construction. Althoughprimarily located under the panel 2, the clutches project through holesin the panel to adjoin the reels and receive the projections 24. Eachclutch contains a rotor 29 which is continually driven by a motor 30located beneath the panel 2. The motor and clutches are connected viaappropriate gearing in gearbox 31 and a driving shaft 32. The drivingshaft is connected directly to one of the rotors with the rotor of theother clutch being driven via pulleys 33 and 34, a belt 35 and anothershaft 36.

The clutches 28 electromagnetically control the driving connectionbetween the reels and the motor. Each reel has an armature plate 37which is secured to its bottom with screws 37a and located adjacent aclutch. When a clutch is electrically energized, via leads 38, amagnetic field is set up which flows through the rotor and its adjacentarmature plate. The plate is attracted and thus magnetically connectedto the rotating rotor. In this manner, the clutches drivingly engage thereels with the motor. The motor supplies a torque of such direction thatwhen either of the reels is engaged to the motor that reel rotates inthe takeup direction.

Preferably, during those periods when the ribbon cartridge is mounted onthe printer but the ribbon is stationary a small current is fed to bothclutches to maintain tension in the rib bon by applying slightcounterclockwise takeup torques on both reels.

As also shown in FIGS. 1 and 2, the device includes a pair of controlarms, 39 and 40, which are pivotally mounted with pins 41 on an L-shapedbracket 42 having one of its legs secured to the underside of the panel2. The control arms project through holes 43 in the panel to locationsadjacent those portions of the scissor arms designated 60 and 7a in FIG.I. These locations are such that each control arm, 39 or 40, isdisplaced by a scissor arm and pivoted about a pin 41 when the scissorarm becomes positioned to indicate that a predetermined low amount ofribbon is in the roll of ribbon which the scissor arm contacts.

When one of the scissor arms becomes located in such a position to pivota control arm, the control arm contacts and actuates a pressure-actuatedswitch, 44 or 45. The switches are mounted on the L-shaped bracket 42with fasteners 46. Each switch includes a spring-loaded contact button47 which is adapted to be depressed by a control arm to actuate theswitch. Each switch controls suitable circuitry via leads, 44a and 45a,for energizing one of the clutches while substantially deenergizing theother. That clutch which controls the rotation of the reel which is in alow ribbon condition is energized to cause this reel to rotate andtakeup the ribbon. The other clutch is substantially deenergized toallow the reel it controls to rotate and payout ribbon.

A small current (much less than that fed to the clutch controlling thetakeup reel) is preferably fed to the clutch which controls the payoutreel. This applies a slight takeup torque to the payout reel andmaintains tension in the ribbon to keep it taunt during feeding.

As an example illustrating the operation of the apparatus, in the stateshown in FIGS. 1 and 2, the ribbon is almost depleted from theright-hand reel 3 and fully wound on the left-hand reel 4. Since theright-hand reel 3 is in a low ribbon condition and the scissor arm 6 isin a position indicating this condition, the apparatus is ready toreverse the direction of ribbon feed. The scissor arm 6 becomespositioned such that its portion designated 6a contact and pivots thecontrol arm 39. The control arm 39 actuates the switch 44 to energizethe clutch 28 which is connected to the right-hand reel 3 whilesubstantially deenergizing the clutch 20 connected to the left-hand reel4. This drivingly engages the right-hand reel 3 with the motor andcauses it to rotate in the takeup direction (counterclockwise in FIG.ll) while the left-hand reel is allowed to rotate (clockwise in FIG. 1)to payout ribbon.

Circuitry for selectively energizing and substantially deenergizing apair of clutches by pressure-actuated switches in this manner is wellknown. One possible circuit is illustrated schematically in FIG. 4. Theleads 44a and 450 from switches 44 and 45 are respectively connected tothe set inputs of a flipflop 50. When actuated, each switch causes apositive going transition to occur on its lead, 440 or 45a. Such atransition on lead 4410 applied to the flip-flops set input causes theflipflop to assume its l state and provide a steady signal at its loutput. A transition on lead 45a applied to the flip-flops reset inputcauses the flip-flop to assume its state and provide a steady signal atits 0" output. Only one of the flipflops two outputs is active at anyparticular time and this out put is determined by the input to which apulse was last applied.

Each of the flip-flops outputs is connected to an input of one of a pairof AND-gates, 51 and 52. Each AND gate normally has a ribbon feed signalfed over line 55 to its other input and, when enabled by an outputsignal from the flip-flop, feeds a signal to activate one of a pair ofcurrent-driving circuits, S3 and 54. Each of the clutches 28 isconnected between a positive potential V and one of the current-drivingcircuits. Thus, each current-driving circuit energizes one of theclutches in response to a signal from the flip-flop.

When the ribbon feed device is operating, the flip-flop 50 is either inits 0 or l state. One of the flip-flops outputs is active and providinga signal to the driving circuit, 53 and 54, which is energizing theclutch controlling that reel onto which the ribbon is being wound. Toreverse the direction of ribbon feed, one of the switches, 44 or 45, isactuated to change the state of the flip-flop 50. This causes thepreviously active current driving circuit to become inactive and thepreviously inactive current-driving circuit to become active.

Before removing the ribbon feed device from the printer, the ribbonfeed" signal on line 55 is terminated to block the signals from theflip-flop 50 to the driving circuits, 53 and 54. This essentiallydisengages the reels from the driving motor 30. During a ribbon feedoperation, a "ribbon feed signal from the printer's control circuit isfed over line 55 to the AND-gates, SI and 52. This signal is providedbefore printing is initiated and after the ribbon feed device has beenmounted on the printer with the scissorlike member 5, reels and otherparts properly situated. Since the state of the flip-flop 50 is onlychanged by actuation of one of the switches, 44 or 45, when a ribbonfeed signal is fed to the AND gates the ribbon will be fed in the samedirection as it was before the ribbon feed" signal was terminated.Feeding in this direction occurs irrespective of the amounts of ribbonon the reels until one of the reels is in a low ribbon condition. Atthis time the direction of ribbon feed is reversed.

FIG. 4 also illustrates another current-driving circuit 56 whichcontinually feeds a small hold current to both clutches to maintaintension in the ribbon. This driver causes very slight takeup torques tobe applied to the reels. Of course, when ribbon is being fed, the smalltakeup torque on the reel paying-out ribbon is overpowered by the pullexerted on the ribbon by the reel taking it up. However, the smalltakeup torque on the payout reel serves to keep the ribbon taunt dur ingfeeding.

A spooling switch 57 is also provided. By closing this switch, theribbon is automatically wound on the reel controlled by that clutchillustrated on the right in FIG. 4. The spooling switch 57 is connectedbetween that clutch and ground poten tial so that closing the switchcauses a greater current to be fed to the clutch illustrated on theright than to the one illustrated on the left. Such an automatic windingoperation could be used, for example, when it is desired to remove andreplace the cartridge.

FIG. 5 shows the ribbon cartridge as stored. The scissorlike member 5and reels are permanently secured within the cartridge. The right-handreel 3 has been removed in FIG. 5 for better illustration. As shown, abottom cover 48 is provided to protect the ribbon and allow easy storageand transportation of the cartridge. The bottom cover contains lips 49which cooperate with the flanges 11 of the housing 10 in the same manneras do those lips 13 used for mounting the cartridge on the panel.

As previously described, the cartridge is easily removed from andmounted on the printer. During removal, the projections 24 on which thereels are mounted easily slide out of the bores 27 in the clutches 28.When placing the cartridge on the printer, the housing 10 is mounted onthe panel as already described.

Generally, when the cartridge is being mounted on the printer it willcontain a new ribbon, substantially fully wound on one of the reels. Oneof the scissor-arms, 6 or 7, will thus be in a position denoting the lowribbon condition of the opposite reel. Since this scissor-arm willcontact a control ann, 39 or 40, when the cartridge is being mounted, acontrol arm might easily interfere with proper placement of thisscissor-arm. As best seen in FIG. 2, the top portion of each controlarm, 39 and 40, is shaped to provide a slanted camming surface downwhich a scissor-arm indicating a low ribbon condition may slide when thecartridge is being mounted. The surface extends from a point on thecontrol arm which the scissor-arm cannot contact when biased against aroll of ribbon on one of the reels (irrespective of how much ribbon ison the reel) to a point which the scissor-arm contacts when the reel isin a low ribbon condition. Thus, the scissor-arm slides in place withoutinterference.

I claim:

1. in a apparatus which bidirectionally feeds an elongated web between apair of reels by rotating one or the other of the reels in a directionto takeup the elongated web thereon and which reverses the direction offeeding when a predetermined low amount of web is on one of the reels,the improvement comprises:

a. a movable open-bottomed housing;

b. a scissorlike member having a pair of scissor arms located within thehousing:

c. means for mounting the scissorlike member within the housing;

d. means for rotatably mounting the reels within the house. biasingmeans for urging the scissor arms against the peripheries of the rollsof web on the reels;

f. a pair of control arms, each of which is adapted to be displaced byone of the scissor arms when the scissor arm is located in a position toindicate that a predetermined low amount of the web is in the rollagainst which it is urged;

g. a pair of switches, each of which is adapted to be activated by oneof the control arms when the control arm is displaced; and

h. drive means, responsive to the switches, for selectively rotatingeither of the reels in a direction to takeup the web thereon when apredetermined low amount of the web is on the reel.

2. The apparatus as recited in claim 1 further including a stationarypanel and wherein the drive means, control arms, and switches arelocated on a first side of the panel, the panel having apertures throughwhich project portions of the drive means control arms.

3. The apparatus as recited in claim 2 and further including means fordetachably mounting the housing on the side of the panel opposite to itsfirst side such that the open bottom of the housing is placed adjacentthe panel.

4. The apparatus as recited in claim 3 wherein a portion of each controlarm is shaped to provide a camming surface over which one of the scissorarms, when in a position indicating that a predetermined low amount ofweb is in the roll against which it is urged, may slide when mountingthe housing on the panel, whereby the control arms do not interfere withthe scissor arm when the housing is being mounted.

5. The apparatus as recited in claim 1 wherein the biasing means urgesthe scissor arms away from each other.

6. The apparatus as recited in claim I wherein the biasing meanscomprises a torsional spring mounted at the pivot point of thescissorlike member.

7. The apparatus as recited in claim 1 wherein the means for mountingthe scissorlike member within the housing comprises a member projectingfrom the top of the housing and jointed to the scissorlike member at itspivot point.

8. The apparatus as recited in claim 1 wherein the drive means comprisesa motor and a pair of electrically controlled clutches each of which isconnected between the motor and one of the reels and adapted todrivingly engage the motor with the reel in response to displacement ofone of said control arms by one of the scissor arms to activate one ofthe switches.

1. In a apparatus which bidirectionally feeds an elongated web between apair of reels by rotating one or the other of the reels in a directionto takeup the elongated web thereon and which reverses the direction offeeding when a predetermined low amount of web is on one of the reels,the improvement comprises: a. a movable open-bottomed housing; b. ascissorlike member having a pair of scissor arms located within thehousing: c. means for mounting the scissorlike member within thehousing; d. means for rotatably mounting the reels within the housing;e. biasing means for urging the scissor arms against the peripheries ofthe rolls of web on the reels; f. a pair of control arms, each of whichis adapted to be displaced by one of the scissor arms when the scissorarm is located in a position to indicate that a predetermined low amountof the web is in the roll against which it is urged; g. a pair ofswitches, each of which is adapted to be activated by one of the controlarms when the control arm is displaced; and h. drive means, responsiveto the switches, for selectively rotating either of the reels in adirection to takeup the web thereon when a predetermined low amount ofthe web is on the reel.
 2. The apparatus as reCited in claim 1 furtherincluding a stationary panel and wherein the drive means, control arms,and switches are located on a first side of the panel, the panel havingapertures through which project portions of the drive means and controlarms.
 3. The apparatus as recited in claim 2 and further including meansfor detachably mounting the housing on the side of the panel opposite toits first side such that the open bottom of the housing is placedadjacent the panel.
 4. The apparatus as recited in claim 3 wherein aportion of each control arm is shaped to provide a camming surface overwhich one of the scissor arms, when in a position indicating that apredetermined low amount of web is in the roll against which it isurged, may slide when mounting the housing on the panel, whereby thecontrol arms do not interfere with the scissor arm when the housing isbeing mounted.
 5. The apparatus as recited in claim 1 wherein thebiasing means urges the scissor arms away from each other.
 6. Theapparatus as recited in claim 1 wherein the biasing means comprises atorsional spring mounted at the pivot point of the scissorlike member.7. The apparatus as recited in claim 1 wherein the means for mountingthe scissorlike member within the housing comprises a member projectingfrom the top of the housing and joined to the scissorlike member at itspivot point.
 8. The apparatus as recited in claim 1 wherein the drivemeans comprises a motor and a pair of electrically controlled clutcheseach of which is connected between the motor and one of the reels andadapted to drivingly engage the motor with the reel in response todisplacement of one of said control arms by one of the scissor arms toactivate one of the switches.